The proposed research is concerned with mechanisms of sound communication in an insect, Gromphadorhina portentosa, that uses its respiratory system to produce hisses. It uses these hisses in several kinds of social interactions. This preparation offers a chance to analyse the morphological and physiological changes underlying the development of sound production in individuals, to determine the specific changes that have led to specialization of part of the respiratory system and its innervation in the course of evolution, and to ascertain the physiological basis of sound reception in this species. In the coming year we will be dealing in particular with the details of sound reception -- both physiological and anatomical aspects -- and with the effects of sound signaling on the behavior of conspecifics. Our experiments are directed to increasing our understanding of auditory physiology in this species, and towards determining the extent to which organisms that have evolved sound communication independently (e.g. other acoustically active insects) towards a similar neural organization for dealing with auditory signals.